(disclosure: I work on iroh): you're selling yourself short! All of this is accurate, except for maybe the BGP stuff :)

Dumb Pipe & Sendme me are indeed demos, we do provide a set of default, public relays to use for free. The relay code is also open source, and if you want to pay us we can run a network for you.

We try to provide a few different options for discovery, the one we think has the most general utility is a custom DNS server, but both local mDNS and Bittorrent Mainline are also pluggable options.